Fixed wildly incorrect result from log2 function in 32-bit builds. (&…

… added test to prove it)

src/chaining_hash_table.c

@@ -187,7 +187,7 @@ void genc_cht_destroy(struct genc_chaining_hash_table* table)
 
 static GENC_INLINE int genc_log2_size(size_t val)
 {
-	return val == 0 ? -1 : (int)(sizeof(size_t) * 8 - 1 - __builtin_clzll(val));
+	return val == 0 ? -1 : (int)(sizeof(size_t) * 8 - 1 - __builtin_clzl(val));
 }
 
 static GENC_INLINE int genc_log2_size_roundup(size_t val)

test/chaining_hash_table/cht_inline_test.c

@@ -0,0 +1,13 @@
+#include "../../src/chaining_hash_table.c"
+#include <assert.h>
+
+int main()
+{
+	assert(-1 == genc_log2_size(0));
+	assert(sizeof(size_t) * 8 - 1 == genc_log2_size(SIZE_MAX));
+	assert(0 == genc_log2_size(1));
+	assert(1 == genc_log2_size(2));
+	assert(1 == genc_log2_size(3));
+	assert(2 == genc_log2_size(4));
+	return 0;
+}